There is a proliferation of wireless devices that are able to access and store more than simple phones numbers. These devices can store emails, contacts, files and access confidential information stored securely behind corporate firewalls.
In addition to gaining access to this data it may not be necessary to have a wireless subscription at all. This means that the wireless device could be lost or stolen and still be able to receive data. Even if the device is reported lost the confidential data may still be accessed, if the access is still turned on.
In another scenario, a user could loan their wireless device to a friend or co-worker. The device is not lost or stolen however that new individual is able to access emails or files on that device or behind the firewall without the other person's knowledge. Furthermore this third party also has access to new data that is transmitted to the device where the sender believes the intended recipient to have the wireless device.